/Engine/Plugins/NetcodeUnitTest/NetcodeUnitTest/Source/NetcodeUnitTest/Classes/MinimalClient.h
Writes the NMT_Login message, as a part of SendInitialJoin (separated to make it overridable)
virtual void WriteControlLogin ( [FOutBunch](API\Runtime\Engine\Net\FOutBunch) * ControlChanBunch )